Mobile Home or Householder Application?

Householder Annexe Application vs Certificate of Lawfulness for Annexes

If you’re planning a granny annexe, and it could be built in a way that meets the definition of a mobile home, you might benefit from a strategic move. Consider submitting both a Householder Application and a Certificate of Lawfulness application. This “dual approach” essentially gives your project two chances of getting approved by the local planning authority.

Householder anexe application

Householder Annexe Application for traditionally built Annexes

This is the most common and successful method for most granny annexes, here’s why:

  • Applies to traditionally built structures: Householder applications are for permanent structures, built using conventional building methods.
  • National and Local Planning Policy Assessment: Applications are evaluated against established planning guidelines, ensuring your project aligns with the area’s development goals.
  • Consultation Process: Your neighbours, local council, and relevant specialists (ecology, highways, heritage) are consulted to consider potential impacts.

Certificate of Lawfulness for Mobile Homes

This option can also be explored if a Householder Application seems unlikely to succeed. However, there are limitations with this approach:

  • Mobile Home Definition Requirements: Your annexe must strictly meet the legal definition of a mobile home under the Caravan Act.
  • Ancillary Use Only: This mobile home/annexe can only be used to support the main dwelling

If successful, this route bypasses the need for full planning permission.

Dual Application Approach: Maximise Your Chances

Summing up, if your granny annexe has the potential to be classified as a mobile home, consider submitting both a Householder Application and a Certificate of Lawfulness application.   By submitting both applications simultaneously, you increase your chances of securing approval. If the Householder Application is successful, you have a permanent annexe built to your specifications. If the Certificate of Lawfulness is approved, you can use your mobile home granny annexe without needing formal planning permission. It’s a win-win scenario, offering flexibility and potentially faster approval through the Certificate of Lawfulness route.

NAPC Your Partner in Granny Annexe Planning

All things considered, specialist advice will be needed to ensure your annexe meets the requirements of the Caravan Act. With this in mind, read our blog below, and contact NAPC today at 01285 283200 to discuss your project. Above all, we will help you to determine if the dual application route is suitable for your annexe.

The Caravan Act – Everything you need to know



Get an answer quicker with a Feasibility Study

A one-off Feasibility Study (from £99) will equip you with crucial planning insight about the area you’re planning to site your Annexe or Garden Room. So if you pursue your application, you have the best chance of success. 

Prefer to talk to a planning expert in person?

Book a call with one of our planning experts or call/email us directly.

Phone number

01285 283200


Related posts


Annexes are now a popular addition to many family homes to provide additional accommodation.

Mobile Home

NAPC provide a service to help you establish whether your mobile home meets the definition of a caravan and can apply for a Certificate of Lawfulness

Garden Room

Looking to install a garden room at your property? Unsure about planning permission or building regulations for garden rooms?

Planning Info For...
Planning Services

Talk to a planning expert

By completing the form below, or you can call us direct: